RFU Chairman Bill Beaumont claims the IRB's refusal to move the Test centres on a disagreement regarding the start of the June window.

"We made a request to the IRB because they interpreted the weekend of May 31-June 1 as a June weekend, and we maintain it is a May weekend," Beaumont told The Rugby Paper.

"We've tried for some time now to get it changed, but to no avail."

An IRB spokesman hinted the RFU had failed to lodge their complaint in time to have the fixture list altered.

"When the Test schedule was agreed in 2010 the RFU was going through administrative changes. At that time they were asked to respond to the schedule, and that did not happen, so the schedule was drawn up as is," said the spokesman.